The invention relates to an auxiliary coupling disk adopted for use on a miniature vibration voice-coil motor to couple with a magnetic weight element to enable the magnetic weight element to move away from motor rotational center to generate desired vibration during rotation.
U.S. Patent publication No. 20020195890 entitled xe2x80x9cDC BRUSHLESS VOICE-COIL VIBRATION MOTORxe2x80x9d discloses a DC brush less voice-coil vibration motor that has an induction coil and a magnetic weight element which has a plurality of coplanar magnetic poles to serve as the stator and the rotor of a miniature motor. It further provides an auxiliary coupling disk to couple on a spindle in a coaxial manner. The auxiliary coupling disk is made from magnetic material. The magnetic weight element is directly attracted and attached to the auxiliary coupling disk. The magnetic weight element has a smaller diameter than the auxiliary coupling disk. Hence the magnetic weight element may move to one side of the auxiliary coupling disk and move away eccentrically from the spindle. When electric energy is input in the induction coil and an induction magnetic field is generated to produce interaction with the magnetic weight element, the magnetic weight element may generate rotational energy. As the magnetic weight element is eccentric from the spindle, the inertia of the magnetic weight element will generate vibration energy during rotation.
By means of the patent mentioned above that consists of an induction coil and a magnetic weight element of a plurality of coplanar magnetic poles, a miniature motor with a diameter smaller than 20 mm can be produced. The eccentric magnetic weight element can produce required vibration. It can be used in mobile phones or the like to provide incoming call vibration. The vibration energy depends on the moving distance of the magnetic weight element spaced from the spindle. The greater the moving distance, the greater the vibration becomes. Smaller moving distance also produces smaller vibration. Hence to increase the vibration, the simplest way is to shrink the diameter of the magnetic weight element. However, the magnetic weight element must have sufficient space to interact with the induction coil to generate rotation. Hence there is a dimensional limitation for the magnetic weight element. The actual size of the DC brush less voice-coil vibration motor made according to the aforesaid patent is about 20 mm or less. As the dimension of the magnetic weight element is limited, the vibration generated by the DC brush less voice-coil vibration motor is also limited.
Because the miniature DC brush less voice-coil vibration motors made by the conventional techniques have vibration constraint, the primary object of the invention is to provide an auxiliary coupling disk to change vibration within a limited space so that vibration energy can be increased for the DC brush less voice-coil vibration motor within a limited space.
The auxiliary coupling disk for miniature vibration voice-coil motors of the invention includes an auxiliary coupling disk, which is a circular made from magnetic material. The circular disk has a vertical peripheral wall and an aperture in the center. One side of the circular disk close to the peripheral wall has one or more removable members, which may be removed from the circular disk. By means of such a design, the magnetic weight element may move away from the spindle opposing the removable member. When the magnetic weight element has a maximum eccentric displacement relative to the auxiliary coupling disk, if there is a desire to increase vibration, the removable members may be selectively removed to reduce the weight of the circular disk to offset the magnetic weight element, to increase vibration.
The auxiliary coupling disk for miniature vibration voice-coil motors of the invention may include one or more removable members in a limited space. Through reducing the weight of the circular disk to offset the magnetic weight element, the removable members may be selectively removed according to requirements to adjust and increase vibration.
The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.